The environmental consultant says that at least four survey visits of impacted water bodies are required between mid-March and mid-June. Two of these must be completed between mid-April and mid-May.
If the nets are found, then six survey visits are required to determine the concentration of the creatures on-site, and three of these visits must be undertaken from between 15 April-15 May.
According to the company, aquatic survey season runs from 15 March to 15 June but must begin by 25 April; terrestrial season goes from 15 March to 15 September; and environmental DNA survey season runs from 15 April to 30 June.
"If found on-site, GCN can cause major delays to site works," it says.
"Excavations remaining open that are subsequently flooded may result in GCN colonisation if they are present in the area."